To meet the challenging targets in the Climate Change (Scotland) Act 2009 there is a need to consider the carbon costs of public sector activity and spend as a matter of routine and to use carbon assessments to ensure that carbon is factored into all decision making.
There are a number of possible assessment approaches, and the suitability of each depends on the purpose of the assessment. There is no single approach, methodology or tool that fits all circumstances.
There are two basic approaches to choose from:
- Production-based emissions only capture the emissions caused directly by a particular entity - in the case of Scotland this encompasses all domestically produced emissions, and this definition can equally be applied for a local authority area or a public sector organisation.
- Consumption-based emissions are more comprehensive and look at all the emissions that are attributable to the choices/behaviour of a particular entity (including the direct emissions caused by the fuel consumed (i.e. production-based emissions) but also, for example, the indirect emissions caused by the production of procured goods).
There is also a considerable degree of freedom in choosing the emissions that are 'in scope' of the assessment from the perspective of a particular body.
- Direct emissions are those caused by the organisation through industrial process emissions or in the burning of fuels (e.g. for heating or in the use of its own vehicle fleet). These are also called 'Scope 1' emissions, following a convention by the GHG Protocol.
- Indirect emissions are all other emissions. These can be subdivided into 'Scope 2' (indirect electricity) and 'Scope 3' (indirect other). The Scope 3 category is very wide and not assessed easily. Emissions embedded in - caused by the production of - goods and services procured from others are a key element of indirect emissions.
A complementary way to view emissions follows the function of a business entity and its interactions with suppliers and customers:
- Corporate/Operational emissions arise from the day-to-day running of the organisation ( Scope 1 emissions and may include Scope 3 emissions - depending on how wide the influence of the organisation is to be drawn. Business travel emissions might be included as the extent of those depends on modal choices that are within the control of an organisation).
- Upstream emissions are caused by the supply chain to an organisation (these include Scope 2 and 3 emissions).
- Downstream emissions are caused by the use of the outputs of an organisation (all Scope 3).
For the appraisal of Government policies, the focus is on the differential impact of policy measures on emissions - i.e. the change in emissions arising from the introduction of a policy. The Department for Energy and Climate Change has produced specific guidance to help assess proposals leading to an increase or a reduction in energy use (including transport fuels) and GHG emissions.